Cut the aubergine into 2 cm thick slices, season with salt, pepper and place in a large baking dish (tray or similar with a slightly raised edge). Quarter the tomatoes and place on the aubergine slices, cut the spring onions and garlic into rings or dice and place them on the tomato and aubergine unit. Cut the feta into small cubes and sprinkle on top and then pepper again and spread the vegetable stock with a small cup of water on the casserole, add oil and place in the oven at 170-200 degrees for 40 minutes.